U.S. patent number 4,023,034 [Application Number 05/611,524] was granted by the patent office on 1977-05-10 for light admitting means for photocell-controlled lighting fixture.
Invention is credited to Ezra L. Schacht.
United States Patent |
4,023,034 |
Schacht |
May 10, 1977 |
Light admitting means for photocell-controlled lighting fixture
Abstract
Fixed indoor ceiling-mounted lighting fixtures can be
inexpensively and simply dimmed automatically in response to
natural daylight availability, by photocell-controlled relay. An
illustration of the technique is shown for modification of a
two-ballast four-lamp fluorescent fixture, to reduce consumption of
electrical energy by fifty percent when daylight permits.
Inventors: |
Schacht; Ezra L. (Houston,
TX) |
Family
ID: |
24449374 |
Appl.
No.: |
05/611,524 |
Filed: |
September 8, 1975 |
Current U.S.
Class: |
250/227.11;
250/239; 385/16; 362/276 |
Current CPC
Class: |
G02B
6/0005 (20130101); F21V 23/0464 (20130101) |
Current International
Class: |
F21V
8/00 (20060101); F21V 23/00 (20060101); G02B
005/14 () |
Field of
Search: |
;250/239,227
;350/96R,96B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Nelms; David C.
Claims
What is claimed is:
1. Light-admitting means for recessed-troffer lighting-fixture,
comprising:
photocell-controlled relay within said lighting fixture
compartment;
cutting-edged coring tube having driving means for penetrating a
ceiling;
light-admitting conduit having light-impervious sheath of diameter
smaller than inner diameter of said coring tube; and
optical coupling means from said light-admitting conduit to said
photocell-controlled relay.
Description
BACKGROUND OF THE INVENTION
New United States government recommendations for energy
conservation through reduction of lighting levels, as well as
escalating costs of electrical energy, make the use of daylight in
buildings, when available, highly desirable. A casual inspection of
many office buildings will show that lighting fixtures are on while
the contributed daylight through the windows makes the use of at
least a part of the interior lighting unnecessary.
Common methods of construction today employ suspended ceilings with
fluorescent lay-in or troffer-type fixtures supported on such
ceilings. Popular fixtures are the four-lamp fluorescent type,
usually with two ballast transformers. It is desirable to control
at least one of these ballasts and its two lamps by photoelectric
response to daylight. Photocell controlled relays are well known in
the art, but a relay of this type, installed within the wiring and
ballast compartment of a fixture, requires a simple method of
access to the daylight upon which its operation depends.
OBJECTS AND SUMMARY OF PREFERRED EMBODIMENTS OF THE INVENTION
Accordingly it is a primary object of the present invention to
provide a simple light-admitting method to photocell controlled
relays located within the body of the lighting fixture.
It is a further object of the present invention to make the
installation so simple that a minimum disturbance to fixture or
building structure is required, and that the work required be
within the capability of the maintenance personnel now qualified to
replace lamps and ballasts.
It is a further object of the present invention to make the
installation of such light-admitting means simple for manufacturers
of the lighting fixtures.
Other and further objects will become apparent to those skilled in
the art, upon consideration of the following detailed description
and with reference to the following drawings, wherein like elements
have been identified with like numerals, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded pictorial view of a recessed lighting fixture
and supporting ceiling, with light pipe;
FIG. 2 is a sectional view of installing tool and light pipe or
conduit; and
FIG. 3 is a cross-sectional view of the fixture, showing ballast
compartment and light-admitting fitting.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE PRESENT INVENTION
With reference now to FIG. 1, there may be seen an apparatus of the
present invention. The suspended ceiling, of which one panel 1 is
shown, is mounted on a framework of T-bar-like members 2, which
also serve to support lighting fixture 3. Lightpipe 4, consisting
of a covered acrylic rod of small diameter, extends from wiring
compartment 5 through hole 7 over T-bar 2 through ceiling panel 1.
Light enters end of pipe 4, from room under ceiling and strikes
photocell (not shown) in fixture wiring compartment 5. Ballast 6 is
energized or deenergized as the level of daylight for which the
control has been calibrated demands. Hole 7 has been drilled for
passage of light pipe 4 from inside of fixture 3, to avoid
necessity of removing any ceiling panels.
With reference now to FIG. 2, the technique of installation is
shown. A metal tube 8, somewhat larger in internal diameter than
lightpipe 4, has a cutting edge 9, which can be pushed through the
ceiling panel 1, usually made of soft acoustic material, from
inside fixture 3 through hole 7. Lightpipe 4, consisting of acrylic
rod 10, covered with light-impervious sheath 11, and terminating in
acrylic light-spreading and diffusing button 12, is then inserted
through tube 8 from fixture 3. Tube 8 may then be withdrawn through
ceiling panel 1, removing core of ceiling material, and exposing
end 13 of lightpipe 4 to room light.
Button 12 is positioned against face of photocell (not shown), in
the manner shown in my patent application Ser. No. 606,745, filed
on Aug. 22, 1975, for improvements in photocell controlled
circuits.
The photocontrol is then wired to control ballast 6 in response to
any previously calibrated daylight level. It has not been necessary
to remove ceiling panel 1, or to damage it except for a one-quarter
inch diameter hole through which end 13 of lightpipe 4 is exposed,
and there has been no damage to fixture lens or louver.
With reference now to FIG. 3, in an alternative method, a hole may
be punched in cover 15 of the ballast compartment 5, coaxially with
a hole 16 in louver or lens 17, at either end of fixture 3.
Lightpipe 14 is a right-angled acrylic rod, although other
materials may be used, adjusted to see daylight from a nearby
window.
It, therefore, may be seen that the present invention is well
adapted to attain substantially all of the objects and advantages
hereinabove set forth together with other advantages which will
become apparent from the description of the apparatus. This
description, including the alternative embodiment, is intended as
illustrative of the concept of the present invention, and it is
intended that other embodiments be considered as falling within the
spirit and scope of the present invention.
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